


You Won't be Seventeen Forever and We Can Get Away with this Tonight

by andthenonawednesday



Category: Teen Wolf (TV)
Genre: Knotting, M/M, Sexy Times, deaged!derek
Language: English
Status: Completed
Published: 2014-07-02
Updated: 2014-07-02
Packaged: 2018-02-07 05:16:39
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 1
Words: 1,769
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1886469
Author URL: https://archiveofourown.org/users/andthenonawednesday/pseuds/andthenonawednesday
Summary: <blockquote class="userstuff">
              <p>Based on a tumblr prompt~~ <br/>Derek and Stiles are mates. They've had sex, but Derek has never knotted Stiles before, and being in a 17 year old body again leads to a slip in his control. Hijinks ensue.</p>
            </blockquote>





	You Won't be Seventeen Forever and We Can Get Away with this Tonight

Stiles woke up when he felt the bed dipping next to him. He recognized the scent of Derek’sdeodorant, and Immediately rolled over, allowing more room for him to crawl under the covers. 

“What’s wrong Derek? It’s almost 4 in the morning? You heard my dad when he said that even if you younger than me, you weren’t allowed in my-..” But he cut off mid-sentence when he realized that Derek’s eyes were glowing blue in the dark. “Are you okay, Der?”

 

“I know we’re not supposed to, but it’s so close to the full moon. I tried sleeping on the couch, but I couldn’t calm down. I just needed to be close to you..” As Derek talked he snuggled in close to Stiles, nestling his head onto the pillow next to him, so their chests slotted together and their legs tangled up. “You know I hate sleeping away from you when I feel like this…” Derek’s voice drifted off into Stiles’s hair. 

 

“I know, I know. It’s okay, my dad won’t be up for a few hours anyway. Just keep your ears open for him wolfboy.” Stiles’s arms snaked up around Derek’s shoulders, pulling him even closer. “We’ve all had a rough couple of days, but I promise we’ll find a way to turn you back. You won’t be 17 forever.” Stile’s hands traced the invisible path of where the triskelion tattoo used to be. They lay there together for a few moments, Stiles rubbing Derek’s back in soothing motions. Derek began fidgeting again, and when Stiles felt something firm against his hip, he couldn’t help but laugh a little. “I guess even little Derek is feeling the effect of being 17 again isn’t he?” 

 

Derek buried his face further into Stiles shoulder, mumbling, “Shut up. It’s not my fault. Just being close to you gives it a mind of its own…” Stiles continued to laugh, but just thinking about Derek having an erection soon made his dick perk up in interest too. 

 

Stiles pushed Derek’s shoulders back, giving him access to his face. He could see the faint blush there, and Stiles couldn’t help but kiss him. “Hey, I am definitely not complaining about the rise in your libido.” Stiles muttered, smattering his lips along Derek’s mouth, cheek, jaw. Soon, Derek began kissing him back, opening his mouth and letting Stiles tongue skim across his own.

 

Derek’s arms came up, grasping Stiles’s shoulders, his fingers digging into the skin as he rocked forward, rubbing his erection against Stiles’s through their pajama pants. Stiles pushed himself up a few inches, smirking down at Derek before he started kissing his way down Derek’s chest. 

 

Derek’s breath hitched as Stiles long fingers dipped beneath his waist band, pulling his pajamas down and his dick slapped onto the smooth skin of his stomach, aligned with the fine trail of hair below his bellybutton. Stiles tongue began grazing across the tip, and then he was bobbing his head up and down, nearly swallowing the entire shaft as his tongue curled around the head. Derek’s claws were digging into the sheets, and after only a few moments he jerked away, pulling Stiles back up the bed and flipping them over in one fluid motion.He kissed the smug look off of Stiles’s face, and slid down the bed, peppering him with kisses as he went. 

 

Derek ripped Stiles’s pajamas off, and before Stiles could bitch about the cost of another piece of shredded clothing, Derek had his knees pushed up and was planting an opened mouth kiss onto the pink ring of skin he had grown to love so much. Stiles squirmed on the bed, shoving his fist into his mouth to suppress the noises that were leaking out. Derek’s tongue danced around his hole, sporadically plunging in and making Stiles keen. Stiles could feel the sharp prick of Derek’s fangs gently grazing his skin, and soon he was begging Derek for more. 

 

Stiles grabbed the lube from inside his pillowcase, and threw it at Derek, begging him to slick his cock up. After applying a generous amount to both himself and Stiles, Derek was aligning the blunt head of his dick against Stiles’s entrance. Stiles’s legs wrapped around Derek, ushering him closer, and Derek slipped inside. 

 

As Derek’s rhythm picked up, he dropped down to his elbows, bracketing Stiles’s face with his arms. Their mouths met, both licking into the other’s mouth with ferocity. Soon, Stiles began babbling out words into Derek’s open mouth. He panted, “I love you. I love you. I was so scared when we found you and you were so young again and you looked so scared. Then you woke up and you didn’t recognize anyone and I thought that I had lost you, but you looked into my eyes and I saw it all coming back to you and I swear to god I’ll get her back for this Derek I’ll never let her hurt you again.” Stiles’s words all came bubbling out, punctuated only by the edge of a moan when Derek went especially deep. Derek’s eyes were glowing blue again and he grabbed Stiles’s face, turning it to the side so he could suck a hickey into his neck, whispering “I love you too. You’re never going to lose me. You’ll always bring me back. You’ll always bring me back, you’re my anchor. I love you.” Derek’s intensity began to pick up, and he pounded into Stiles at an even faster pace, pushing these little breathless moans out of him. 

 

Stiles began to clench around Derek, as his dick began to shoot white ropes of cum between them, and feeling the white-hot heat around his dick, sent them both over the edge together. Stiles was expecting to feel the warmth flood him, like he typically did when Derek came inside of him, but instead he felt Derek’s cock expanding within him, stretching the skin around his rim even tighter. “Der, what’s happening? What are you doing?” Stiles had started to panic, already forgetting his own afterglow. Derek’s face was scrunched up, his eyes squeezed shut as a silent scream ripped through his mouth. Then Stiles felt the pulsing within him, the telltale sign of Derek’s orgasm.  

“Stiles, I’m sorry. I-I-I knotted you. I didn’t mean to. Are you okay?” Derek’s voice shuddered. He bent down, kissing Stiles on the forehead. 

“It’s okay. It’s okay. I just wasn’t expecting it. It’s big though, like REALLY FUCKING BIG. How are you going to get it out?” Stiles was still a little breathless, but he was determined to stay calm. 

Derek pressed their foreheads together, sighing as he admitted,”I can’t get it out. We just have to wait for it to go down on its own…” Derek’s arms were shaking now, but he was trying to hold as much of his weight off of Stiles as he could.

“So you’re saying, that your dick inflated inside of me like a balloon animal, and now we can’t even get it out?” Stiles squirmed against Derek, the cum on their chests already beginning to dry and glue them together. 

“I’m sorry Stiles. Normally I can control it, but I guess I forgot how it felt for my penis to be 17 again. It was a little more intense than I’m used to…” Derek was blushing again. 

  
A few minutes later and they had maneuvered until they were both on their sides, still slotted together. Derek was running his hands through Stiles’s hair, and planting soft kisses onto the back of his neck. He whispered sorry, again and again, but each time Stiles brushed it off. After around ten minutes though, Stiles couldn’t keep his thoughts inside anymore, and sounding timid for once said, “Derek, I thought that knotting was rare… I thought it only happened between mates.” His voice trailed off, and Stiles could feel Derek freeze behind him.

 

“It is very rare. This is the only time it’s ever happened to me…And I was hoping that I could wait for the right time.” Derek sounded like he was the one panicking now. “I’m sorry I didn’t tell you, but I knew it would be unfair if I did. I wanted to wait until you were older, so you’d know what you were getting yourself into..” 

 

Stiles lay there quietly for a few moments, then he began to giggle. Derek stiffened behind him, and his voice sounded gruffer when he said, “Stiles, it’s really not that funny to me. I’m sorry it happened like this, but it’s still a big deal.” Stiles flipped them over again though, until he was straddling Derek. He placed his finger on Derek’s lips, shushing him, as he repressed his own giggles.

  
“Derek I’m not laughing at you. I’m laughing at your penis and at your bad luck. All this time you’ve known I was your mate, but you were waiting to tell me. I’m sure you had some huge, romantic scene planned out in your head. I’m sure you wanted to wait until I was done with college and you deemed me ready to settle down. I’m sure you were going to pick out some huge diamond and get down on one knee and pretend I was some heroine from the 50’s.” At this point Derek tried to interrupt again, but Stiles mashed his fingers firmer into Derek’s lips and continued on, “But baby, that’s not how our lives work. We’ll be lucky if we both survive long enough for me to graduate college. Our lives are more like a horror movie, not a romcom. You wanted to wait until the right time to tell me I was your mate? Well guess what, your dick beat you to it. And I know that I’m young, and I know you’re probably scared this isn’t what I really want, but I don’t need your dick to tell me I’m your mate. My heart figured it out a long time ago.” Stiles finally removed his hand from Derek’s mouth, but instantly replaced it with his own. They kissed long and slow, and Derek could feel Stiles melting onto him.It wasn’t long until their kissing became heated again, and Stiles began to rock back and forth on Derek’s knot. 

 

“Stiles, you do know that this means we’re going to be stuck together even longer if we go again, right? Derek gripped Stiles’s hips, trying to still him.

 

“Aw babe, we’re stuck together forever. Your penis just told me. What’s a few more hours added to it?” Stiles giggled again as Derek flipped them over again. 

 

**Author's Note:**

> Hey guys! I hope you liked it, and if you didn't I apologize! This is my first time posting a fic since way back in the day when I was writing Harry/Cedric fics on fanfiction.net. Soooo, be gentle with me?
> 
> Also if you want to follow me on tumblr or send me Sterek prompts of your own, you can find me at hoechlinmypanties.tumblr.com


End file.
